Tobacco use in the United States is responsible for more than 400,000 deaths per year due to many types of cancer and cardiovascular disease (See, Office of Smoking and Health, The Health Consequences of Smoking: Nicotine Addition, A Report to the Surgeon General, U.S. Government Printing Office, Washington, D.C., DHHS Publication Number (CDC) 88-8406 (1988)). Despite the grave consequences of tobacco use, the vast majority of tobacco users are unable to abstain from nicotine use for any extended period of time. One reason for this inability to abstain from nicotine use is the weight gain experienced by most tobacco users in the post-cessation period, with this being especially true for female cigarette smokers.
The relationship between tobacco use and decreased body weight has been known for more than 100 years. It has been well established that smokers weight less than non-smokers. Recent research has shown that nicotine is the substance responsible for the decreased body weight of tobacco users (See, Chapter on Nicotine Dependence, The National Institute on Drug Abuse's Fourth Triennial Report to Congress, In Press). Two major factors related to nicotine use cessation are responsible for weight gain in the post-tobacco cessation period including 1) decreased metabolism and/or 2) increased dietary intake. Conversely, it must be the case that nicotine use results in increased metabolism and/or increased dietary intake. In humans, intravenous nicotine infusion was shown to modestly increase the resting metabolic rate (6.5%) of smokers and non-smokers similarly. Also, in smokers and non-smokers alike, nasal nicotine solution insufflation significantly reduced the perceived taste intensity of dietary "fat", but not "sweets". From this, it appears that nicotine acts to decrease body weight through decreased calorie intake (i.e., appetite suppression) and increased metabolism. The mechanism for the observed appetite suppression is likely related to the increased serotonergic activity within the hypothalamus of the brain.
In an attempt to reduce post-cessation weight gain and achieve long-term tobacco cessation success, the affects of nicotine replacement (nicotine gum) on post-cessation weight gain were examined over a ten week post-cessation period. Nicotine gum when compared to placebo was shown to reduce the weight gained in the post-cessation period by approximately 50 percent (3.8 versus 7.8 pounds, respectively), and the magnitude of this beneficial effect was related to the amount of nicotine gum used. Similarly, it was found that nicotine gum use by abstinent cigarette smokers reduced the frequency and severity of self-reported "Hunger" scores and self-reported eating over the first month of nicotine abstinence. Increases in self-reported measures of hunger are likely related to increased weight gain in the post-cessation period (See, chapter on Nicotine Dependence, The National Institute on Drug Abuse's Fourth Triennial Report to Congress, In Press). As a result of the above findings, the use of an appetite suppressant, therefore, should prevent post-cessation weight gain in nicotine-experienced individuals.
Past cessation intervention strategies to reduce weight gain during smoking cessation have been attempted. The use of phenylpropanolamine gum, an appetite suppressant, was able to prevent weight gain in female cigarette smokers during two weeks of abstinence. In cigarette smokers attempting to quit, fluoxetine, a serotonergic agonist, was able to prevent the weight gain associated with cessation, as well as inducing decreased caloric intake during a test situation (See, chapter on Nicotine Dependence, The National Institute On Drug Abuse's Fourth Triennial Report to Congress, In Press). As a result, it appears that the use of an appetite suppressant during tobacco use cessation will reduce post-cessation weight gain and increase abstinence success.
Presently, while nicotine appears to act as an appetite suppressant through serotonergic mechanism and is partially effective in preventing the weight gain associated with tobacco use cessation in nicotine-experienced individuals and/or is able to increase metabolism and decrease caloric intake in nicotine-naive individuals, nicotine delivered through various forms of approved nicotine pharmacotherapies is toxic and not recommended for long-term use due to its adverse health effects and abuse potential due to nicotine's addicting nature.